Hydraulic apparatus for motor vehicles



Jan.21,1941. QRGALANOT 2,229,561

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@amdlle 7? Gcflanot Patented Jan. 21, 1941 PATENT OFFICE HYDRAULIC APPARATUS FOR Moron VEHICLES Camille P. Galanot, Cleveland, Ohio, assignor to The Galanot Products Company, Alliance, Ohio,

a corporation of Ohio Application July 14, 1938, Serial No. 219,289

4 Claims.

This invention relates to motor vehicles provided with dump bodies and/or other equipment operated by hydraulic means, and more particularly to so-called dump trucks having bodies pivotally mounted on the vehicle frame at the rear end or one or both sides thereof and provided with a hydraulic jack adapted to raise and lower the body as desired. 1

A general object of the present invention is the provision of novel and improved hydraulic apparatus for vehicles of the type mentioned, which apparatus is especially rugged in construction, and is provided with safeguards against leakage, so that the apparatus is adapted to be used for long periodswithout replenishment of the operating fluid.

A further object of the present invention is the provision of hydraulic hoist apparatus in which the reservoir for the operating fluid is employed as astrengthening member of the vehicle frame and also as a support for the hydraulic jack.

A further object is the provision of a hoist apparatus embodying a novel mode of mounting the'jack upon its supporting frame member, such that the communication between the jack and its associated reservoir, pump, and valves is accomplished by internal conduit means, there being no exposed conduits orflexible conduits required.

Another object of the present invention is the provision of a novel operating valve for use in connection with hydraulic apparatus of the type r in question.

A further object is the provision of valve means including a check valve which opens to admit operating fluid into the fluid operated mechanism, closes automatically when the flow of fluid into the mechanism ceases, and is automatically and positively opened when the operating valve is placed in pressure-relieving position.

Another object of the present invention is the provision, in a hydraulic apparatus of the type mentioned, of a novel pressure operated relief valve for by-passing the operating fluid from the high presssure side of the pump to the low pressure side or to the reservoir when the fluid pressure exceeds a predetermined value, said valve being so constructed and arranged that the fluid is by-passed at a very low pressure after the valve is once opened. I

An additional object is the provision of a novel form of hydraulic jack having automatic relief means by which the necessity of a pressure-operated relief valve may be avoided.

Another object is the provision, in hydraulic hoist apparatus of the typementioned, of novel useful life of the ump is prolonged by the substantial eliminati n of end thrust.

Another object is the provision of aovel form of hydraulic jack including means for,cushloning the end of the stroke of thejack, andfor assisting the load in lowering the jack when the fluid pres-' sureis relieved.

Other and further objects, features, and advantages of the present invention .will be more apparent to those skilled in theart upon a consideration of the following specification-and accompanying drawings-in which-,

Figure 1 is a phantom side elevation of a motor vehicle embodying the novel hydraulic hoist apparatus of the present invention;

Figure 2 is a transverse section through the Vehicle frame just forward of the hoist apparatus, illustrating the mode of support of the latter on the vehicle frame and showing the hoist apparatus in front elevation;

Figure 3 is an enlarged :detail view partly in section illustrating the mode of support of" the operating fluid reservoir on the vehicle frame;

Figure 4 is a side elevation of the hoist apparatus, partly broken away to illustrate the novel relief valve of the present invention;

Figure 5 is a fragmentary section, on line 5--5 of Figure 2;

Figure 6 is a section on line 66 of Figure 5;

Figure '7 is a section on line 1-1 of Figure 2;

Figure 8 is a section on line 8--8 of Figure '7;

of the operating valve of Figure '7, shown in holding, raising and lowering positions, respectively; Figure 12 is a vertical section on the plane of Figure 8, illustrating a modification in which two control valves are employed, the second valve being associated withauxiliary hydraulic equipment; T

Figure 13 is a view similar to Figure 2, illustrating a modification of the present invention Figures 9, 10 and 11 are vertical sectional views Figure 18 is a vertical section, taken longitudlnally of the vehicle, showing a modification in.

the pump and valve arrangement;

Figure 19 is a section on line I 8-I8 of Figv ure 18;

Figure 20 is a fragmentary view similar to Figure 18 and illustrating tral position; and

Figure 21 is a fragmentary view similar to Figure 18 and illustrating the control valve inlowering position.

In order to facilitate a ,n u nderstanding of the invention, reference is made to the embodiments thereof shown in the ,accompanying drawings and detailed descriptive language is employed. It will nevertheless be understood that no limitation of the invention is thereby intended and that various changes and alterations are contemplated such as would ordinarily occur to one skilled in the art to which the invention relates.

Referring first tothe form of apparatus illustrated in Figures 1 to 11, in Figure 1 there is illustrated a motor vehicle having a hydraulically operating pump body designated by the numeral l. The body i is pivoted as at 2 to the rear end of the vehicle frame comprising side frame members 3 and 4 (Figure 2), and is adapted to be supported at its forward end, when in lowered position, upon a cross member extending between two upright sup orts 5 secured to'the respective side frame mem rs. The vehicle may be provided with the usual operator's ca 6, and with the usual. power plant 1 disposed at the forward end of the vehicle frame. The construction thus far described is conventional, and its details form nopart oi. the present invention.

Secured between the side frame members 3 \axnd 4 intermediate the respective ends of the ody i is a member 8 which comprises a combnlation crossirame member and fluid reaser- V01 and also serves as'a support for the hydr ulic jackito be described. The member 8 has a hollow interior, serving as a reservoir, which may be filled to the desired level with an operating fluid, for example oil, through an opening normally closed by athreaded plug 8. The\rnember I is preferably of such a length as to fit exactly between the side frame members 3 and 4, to which itm'ay be bolted or otherwise suitably secured, but may be made in a standard length and adapted to vehicle frames of varying widths by the use of adapters as illustrated in Figure 3. In

\ this instance, an adapter in is bolted to the inner side of each respective side frame member,

the adapter being formed with a recess I I for the reception of a plug I 2 which is threaded into the adjacent end 01 the member 8. The plug i2, when used with n adapter l0 may be either solid or in the formof a hollow ring, but when no' adapter is used the plug l2 obviously must be solid, so as to close the end of the member 8, and render it fluid-tight.

the control valve in neu' Mounted beneath the member 8 is a pump i3. which is adapted to be driven through a shaft [4 from a suitable power take-off l5 which is in turn driven by the power plant 1 of the vehicle, the connection between the shaft l4 and power take-off l5 being manually controlled from the operator's cab by meansof a lever Hi. The details of the power take-off and its connection to the shaft l4 form no part of the present invention and need not be further described.

A fluid operated telescoping jack [1 is mounted centrally of the member8 in a manner to be later described, and is pivotally connected at its outer end as at l8 to the frame of the body I. Mounted on the member 8, adjacent the jack I1, is a 23. This operating means may be duplicated in case two control valves are employed, as later described.

Referring now to Figures 4, 5 and 6, the cross frame member 8, which also comprises the fluid reservoir is provided with a cylindrical journal portion on which the Jack I! is mounted for angular movement in a plane perpendicular to the axis of the member 8. The Jack- I! comprises a collar 25 having an integral disc portion 26 to which the outer sleeve 21 of the jack is bolted. An inner sleeve 28 is slidably mounted within the sleeve 21 for telescoping movement relative thereto, suitable packing rings 28 being provided to prevent the escape of liquid between the respective sleeves. A hollow plunger 30 is slidably mounted within the sleeve 28 and is provided at its outer end with an integral boss 3| for connection to the underframe of the vehicle body I. Suitable packing is employed between the inner sleeve 28 and the plunger 30. V

The collar 25 is provided with a central annular recess 32 forming a channel encircling the member 8 and communicating with a central orifice 33 formed in the disc portion 26 and thus with the interior of the plunger 30. On the interior of the member 8 there is provided a conduit 34 communicating with an orifice 35 in the member 8 which in turn communicates with the annular recess 32 of the collar 25. The conduit 34 is thus in communication with the interior. of the plunger 38 at all times, regardless of the angular position of the jack relative to the member 8, the operating fluid thus being conducted into the Jack entirely through internal. conduit means, eliminating the usual flexible conduit employed for this purpose. Suitable packing rings 36 are provided adjacent the lateral edges of the collar 25 to prevent the escape of operating fluid between the latter and the member 8.

As best seen in Figure 8, the conduit 34 extends longltudinally of the member 8 and thence upwardly, communicating with an orifice 31 in the upper surface of the member 8. The valve casing I8, secured to the upper surface of the member 8,is provided with a conduit 38 communica'ting with the orifice 31 and thus with the conduit 34. The valve casing I9 is likewise provided with an inlet port 39 (Figure 7), a return port 48 and a. pair of by-pass ports 4|, 4| which register, respectively, t rr sp d orifices in the upper surface of the member 8. The orifice 40' which registers with the return port 48 of the valve casing, communicates di- Jack, this angular movement of the latter does rectly with the reservoir comprised in the interior of the member 8. The inlet port 99 communicates with a conduit 42 which extends downwardly through the member 8 to the high pressure side of the pump I9. A conduit 43, branching from the conduit 42 near its upper end, coininunicaltes with the bypass port 4| of the valve casing l9. Each of the said ports 39, 48, 4| and 4| communicates with a cylindrical chamber 44 extending through the valve casing, in which a cylindrical member 45 is slidably mounted. Above the slide member 45 the casing 19 is provided with a conduit 48 in the form of an inverted U.

the respective legs of which terminate in ports 41 and 48 communicating with the chamber 44 at points opposite the ports 39 and 48 respectively. (The conduit 49 opens into a vertical pas-. sage 49 in which is located a check valve 58. The latter comprises a head 5| which is adapted to engage a correspondingly shaped seat member 52, thus closing the passage 49. The valve 58 is normally urged to closed position by a spring 53 under compressionbetween the head 5| and a plug 54, and is provided with an operating stem 55 which extends downwardly into the chamber 44. The conduit 38 (Figure 8) communicates with the passage 49 and thus, when the check valve is open, with the U conduit 48. A horizontal passage 58 likewise communicates with the vertical passage 49, and terminates in an orifice 51 which, as illustrated, is normally closed by a plug 51'.

The slidable member 45 is formed with annular recesses 58 and 59 (Figure '7), and with an intermediate elongated recess 98, into which the valve operating stem 55 extends. The recess 98 is formed with an inclined surface 8| for camming the check valve 58 upwardlywhen-thesllde member 45 is moved to the left. A spring-pressed ball detent 62 is provided for engagement with the walls of the recess 59 when the valve is in neutral or holding position, as illustrated in Figure 7. At the left end of the slide member 45, as shown in Figure '1, there is illustrated the connection between the slide member and the link 23 (Figure 1 through which it is operated.

The several positions of the control valve are illustrated in Figures 9 to 11. Figure 9 shows the valve in neutral or holding position, in which both the inlet port 39 and the return port 48 are closed by .the slide member 45. In this position of the valve, the operating fluidcan flow neither in nor out of the jack l1, which will ac- 5 cordingly remain in the position which it occunects the inletpont 89 and the arm 41 of the U-conduit 48, thus permitting operating fluid under pressure to flow from the pump 9 through the conduit 42, inlet port 39, conduit 48, passage 49 (the check-valve 58 being raised by the pressure of the fluid), conduits 38 and 34 and into the jack IT. The latter will be caused to extend, in the well known manner, tilting the vehicle body In so doing. the Jack is caused to oscillate through a relatively small angle about the member 8, but since it is in communication, through the above described means, with the conduit 44 regardless of the position or the" not interrupt the flow of pressure fluid.

Figure 11 illustrates the slide member 45 in jack lowering position. The recess 58 interconnects thearm 48 of the conduit .48 and the return port 48, and at the same time the cam surface .6l, moving to the leit, has elevated the check valve 58 against the pressure of the spring 53, thus opening a line of communication between the jack l1 and the fluid: reservoir within the member 8. The fluid is thus caused to flow out of the jack, by reason of the load upon the latter, and into the reservoir. Itwill be noted that in the lowering position of the slide member45 the recess 59' .is in communication with the lefthand ends of the elongated by-pass ports 4|, 4|.

The by-pass port 4|, as illustrated in Figure 8, communicates with a conduit 83 disposed inside of the member 8, whichin turn communicates with a conduit'64 provided in a block 65 secured to the member 8 adjacent the valve casing I9. The conduit 84 communicates with the interior of the member 8 through a suitable orifice 66 independent operation of any desired. auxiliary hydraulic equipment, conventionally indicated as a hydraulic cylinder 68.

In this case, the inlet port 68 of the second valve casing 61 communicates with the conduit 42 by means of a branch conduit 18. The valve casing 81 may be provided with all ofthe ports and conduits previously described in connection with the valve casing IS, the conduit correspond-- ing to-the conduit 98 of the valve casing l9 being closed at its lower end by the surface of the member 8, or this conduit may be omitted. The hydraulic cylinder 88 is connected by a conduit 1| with the orifice corresponding to the orifice 51 of the valve casing Hi, the plug 51' (Figure being removed. 7

The by-pass port 4| of the valve casing ii! is in communication with-the by-pass port 18 of the valve casing 61, through the conduit 68, and the by'pass port 13 of the valve casing 81 communicates with the interior of the member 8 through the orifice 99. Thus, when the valve member M of the second valve is. in lowering or neutral posivtion, the by-pass port 4| of the first valve is connected through to the orifice 88. Therefore, when both of the valves are either in lowering or neutral position, the high pressure fluid in the con 1 duit 42 is-by-passed back to the reservoir, just as in the case when a-single valveis used,

By virtue of the provision of a second valve casing 81 and itsassociated part, it will be apparent that the hydrauliccylinder 98' or other auxiliary hydraulic equipment may be controlled independently of the hydraulic jack l1, and vice versa. It should be noted that the high pressure conduit 42 is closed off from the reservoir whenever either valve is in raising position. Under these circumstances, however, if the pressure of the fluid becomes sufficiently hlgh,it will be relieved by means of the automatic relief valve hereinafter described.

It will'be apparent that if it is desired to oper ate an auxiliary'hydraulic device in'synchronism with the hoist jack I1, this maybe accomplished by merely connecting said device to the orifice 51 of the valve casing I9. Similarly, if itis desired, with a single valve, to operate another hydraulic device in lieu of the hoist jack, as for example, when the vehicle is to be used as a snow plow, etc., such hydraulic apparatus may be connected to the orifice 51, and the connection between the conduits 34 and 38 interrupted by inserting a plug.

The relief valve referred to above is illustrated in Figure 4, and'comprisesa cylinder 80, preferably formed integrally with the member 8, and extending into the interior thereof and into communication with the high pressure conduit 42. The inner end of the cylinder is provided with a plug 8! having a central aperture 82 providing communication between theconduit 42 and the interior of the cylinder 80, and forming a valve seat for the valve member 93. The latter is-slidably mounted within the cylinder and is nor-' ing a relatively small primary pressure surface lust sufficient to close the aperture 82 when the valve is seated. The conical surface of thevalve member 83 comprises a secondary pressure surface, which is subjected to the pressure of the fluid in the conduit 42 as soon as the valve member 83 has been unseated. The spring 84 is so selected that the valve member 83 remains seated against the plug 8| until'the pressure in the conduit 42 reaches a predetermined relatively high value, at least slightly in excess of that necessary to'operate' the hydraulic jack and auxiliary hydraulic equipment. When the pressure in the conduit 42 reaches the predetermined limit, the valve member 83. is unseated, exposing the relatively large secondary pressure surface to the pressure of the fluid in the conduit 42, which now flows in through the aperture 82 and out through the port 88'into the reservoir. Since the secondary pressure surface is-many times greater in area than the primary pressure surface, it is ap parent that the valve 83 will remain'unseated so long as the pressure in the conduit 42 exceeds a predetermined relatively low value. Therefore, when the jack II, for example, has reached the limit of its stroke and the pump continues to run, if the operator fails to shift the operating valve to neutral position, no harm will be done since the above described relief valve will be promptly actuated as soon as an excessive pressure is developed in the conduit-42, after which the high pressure fluid from the pump will be by-passed.

at a relatively lowpressure, to the reservoir. The

port 81, providing communication between the interior of the cylinder 80 and the reservoir, pre vents the building up of any back pressureon. the valve member 83.

The details of the pump [3 are illustrated in Figures 7 and 8. The pump comprises a casing secured on the underside oi the member'iB as by bolts 9I and communicating with the reservoir withinv the member 8- through a port 92. The casing 90 is also in communication'with the conduit 42 through a; port 93. The casing 90 comprises two oppositely formed outersections 88 and 89 anda' central section 90', which may be securedtogether, as by bolts 94, to form internally thereof a low pressure conduit communicating with the port 92 and a high pressure conduit 96 communicating'with the port 93. The respective outer sections88 and 89 of the pump casing 90 are each'provided with'a painof laterally extending cylindrical portions for the reception of bearing sleeves 91, the said cylindrical portions of the casing members being closed by threaded caps 98, except'that in one-instance a sleeve 98 is employed instead of a cap, in order to provide for a driving connection, as laterdescribed. In each opposed pair of bearing sleeves 91 there is journalled a shaft 99 having a spur gear I00 keyed thereon. One end of the upper or driven shaft 99 is provided with a projecting tongue IOI, fora purpose later described, and for the sake of interchangeability, it is desirable to form the other shaft ends in a similar manner. The annular flanges 91' of the bearing sleeves 9'! serve as wear plates for the teeth of the gears I00.

The sleeve 98' carries a bearing liner I02 in which is journalled a-short shaft I03. The latter is provided at its outer end with a reduced portion I04 to which may be keyed the universal coupling I4 (Figure 1) which is in turn connected to.the drive shaft I4. The inner end of the shaft I03 is provided with a transverse slot forthe reception of ,the tongue IOI formed on the tained by reason of an annular shoulder I06 formed internally of the sleeve 98. A packing escape of operating fluid past the shaft I03.

By virtue of the described construction it is apparent that the shaft I03 may be connected to either end of either shaft 99,'providing for obtaining a proper direction ofrotation of the gears regardless of the location and position of the cated in Figure 8, to'the high pressure side of the pump. Thereby reason of the intermeshing of the teeth of the respective gears, the

fluid is forced-from the grooves between the teeth, up through the conduit 96 and port 93 to the conduit 42. Preferably a drainage outlet I08 is provided as illustrated in Figure 8, since the pump'is the lowermost element of the fluid system.

Figure 13 illustrates a modification of the present invention in which the hydraulic jack or jacks are'mounted on a cross member which serves as a fluid conduit, but in which a separate reservoir is-prov'ided, the operating valve or valves andthe pump being mounted on the reservoir. Thus, referring to Figure 13 the jacks gland I01: is provided in order to prevent the V a 2,229,5ei

I20, I21 are mounted on a tubular v cross-member I22 which is secured between the side frame members of the vehicle asbefore, and serves as a 'cross frame member as well as a fluid conduit and a support for the jacks. The jack I is provided with a collar I23 of a size suitable to be journalled on the tubular member I22. As

before, the collar I23 is provided with an annular channel I24 communicating at I25 with the interior of the jack. The tubular member I22 is provided with a port I26 which likewise communicates with the channel I24. The hollow interior of the member I22 is in communication with the valve casing I21 through port I28 and conduit I28. The valve casing I21 is mounted on a fluid reservoir I30 which may be secured to the vehicle frame at any convenient point and in any suitable manner. If desired, a secondvalve casing I3I may be mounted adjacent the valve casing I21, for cooperation therewith in the manner described in connection with Figure 12. A pump I32, similar to thatfpreviously described, is mounted beneath the reservoir I30 and communicates, through conduits extending within the reservoir I30, with the valve casings I21 and I3I in the manner previously described.

In this embodiment a relief valve I33, similar to that described in connection with Figure 4. is located in the wall of the reservoir I30, as shown. The valve I21 controls the raising and lowering of the jacks I20, I2I, while the valve I3I may be used for independently controlling any desired auxiliary hydraulic equipment.

Figure 14 illustrates a modified form of jack which is universally mounted on the cross member I22. In this case the collar I34 is not journalled directly on the tubular cross member I22, but is journalled on'trunnions I35, I36 provided on a sleeve I31, which in turn is iournalled on the cross member I22. The sleeve I31 is provided with an annular channel I38 which communicates with the conduit in the interior 0! the member I 22 by means of a port I36. The sleeve I31 is likewise provided with conduits I40, I extending within the trlmnion I36, which serve to provide communication between the annular channel I38 and a conduit I42 provided in the collar I34 and communicating with the interior oi the jack. In this manner the jack is at all times in communication with the interior of the member I22, and is adapted" for angular movement with respect to the latter, in a plane perpendicular to the axis or the member I22, and.

also for limited angular movement in a plane containing the axis of the member I22. Angular movement in the latter plane will be necessarily, small, since movement in this direction cannot exceed the amount of play in the connections between the vehicle body and frame. Therefore, provision may be made for maintaining the conduits HI and I42 in constant communication, by slightly widening one or the other in the direction of the relative movement therebetween.

Figure 15 illustrates a further modified form of jack adapted to be mounted on a tubular cross member in the manner heretofore described. The present jack differs from those previously described in the provision of resilient means connecting the inner sleeve and the plunger, thereby cushioning the end of the stroke 0! the latter and serving to initiate its telescoping movement when the control valve is moved to lowering position. Thus, the jack is provided vtion I12 of the jack collar.

with a disc I45 seated against the lower end of the inner sleeve I45 and held in place by means of bolts I41, by which it is secured to a second disc I48, the latter being retained within the sleeve I46 by means of a retaining ring I49. A tie rod I50, threaded into the disc I45, extends upwardly through the disc I40 and within the plunger I5I, and is provided at its lower end with a lock nut I52. The rod I50 is provided adjacent its upper end with an annular projection I53 which has a sliding engagement in a sleeve I54. The latter is provided with an annular flange I55 which rests upon a helical.

spring I56. The sleeve I54 carries a stop member IE1 at its lower end, serving as an abutment for the annular projection I53 when the plunger is raised as will hereinafter be described. The 1 spring I56 is carried on a spring support I58 ,which has a sliding engagement with the rod I50 and is retained against downward movement by a retaining ring I59.

Assuming that the jack has been raised to such an extent that the inner sleeve I46 is fully extended in the middle sleeve I60 and the latter fully extended in the outer sleeve I6I, the pressure of the operating fluid will force the plunger I5I upwardly within the inner sleeve I46. As this occurs the spring. support I58, spring I56 and sleeve I54 move outwardly with respect to the rod I50 until the stop member I51 comes in contact with the annular projection I53, halting the outward movement of the sleeve I54. The succeeding outward movement of the plunger I5I will thus serve to compress the spring I56 between the annular flange I55 of the sleeve I54 and the spring supporting member I58, thus cushioning the latter end of the stroke of the plunger. When the pressure within the plunger is relieved by moving the operating valve to lowering position, the spring I56 will assistthe load on the plunger in initiating the telescoping movement 01 the latter into,

the sleeve I46.

It will be noted that the Jack just described, like that of Figure 13, comprises three sleeves and a plunger, but any suitable number of sleeves may be employed.

Figures 16 and 1'7 illustrate a modified form of jack embodying automatic relief means, making it unnecessary to employ a relief valve, such as that hereinbefore described. Referring to Figure 16 it will be noted that the collar I65 is provided with two annular channels I66, I61. The channel I66 communicates through a port I66 with the interior of the tubular cross member I63 which, in the embodiment illustrated, serves as the fluid reservoir, as described in connection with Figure 2, for example. The channel I66 likewise communicates through a port I10 with a standpipe I1I threaded into the disc por- The standpipe I is open at its upper end, and is provided, a slight distance below its upper end, with a port The channel I61 communicates with a port I14 extending through the disc portion I12, and likewise communicates through a port I16 with the high pressure conduit I16 from the control valve, not shown.

The jack, in this instance, comprises the single sleeve I11 and a plunger I16 slidably mounted therein, the latter being provided centrally of its lower end with an aperture for sliding engagement with the standpipe I1I, suitable packing being provided to prevent leakage of fluid past the outer surface of the standpipe.

In this embodiment the plunger I18 serves as an auxiliary fluid reservoir, in the following manher. When the plunger is in lowered position, it is occupied by operating fluid up to the level of the lower edge of the port I13. As the plunger is raised by the pressure of fluid flowing through the port I14 from the conduit I18, the fluid within the plunger flows through the port I13 and down through the standpipe I'II, annular channcl I66 and port I68 into the reservoir in the cross member I89, where it is available to feed the pump, not shown. When the plunger I18 reaches its fully extended position, the port I13 in the standpipe is opened to the interior of the sleeve IT! and the fluid under pressure, if the pump continues to run, then flows in through the port I13, down through the standpipe, and into the reservoir as previously described. The pressure fluid is thus automatically by-passed to the reservoir, when the jack is in fully extended position. If the control valve is now placed in holding position and the pump stopped, the plunger I18 will settle down until the port I13 is closed oii from the interior of the sleeve I11, thus preventing further flow of fluid from the sleeve into the standpipe. When the control valve is placed in lowering position, permitting the fluid within the sleeve II! to flow out through the port I14 and conduit I16, the plunger telescopes within the sleeve II! by reason of the load upon it. As it does so, the excess fluid which passes into the reservoir in the cross member I69, after the capacity of the reservoir has been reached, is forced up through the standpipe into the plunger. 7,

It is apparent that this construction not only eliminates a separate relief valve but permits the use of a cross member of lesser cross section, since the reservoir provided in the cross member need not be large enough to contain the-entire quantity of operating fluid.

Figures 18 to 21 illustrate a further modification of the present invention, in which the pump, control valve and relief valve are united in a single casing, which is mounted beneath the hollow cross member which forms the fluid reservoir. In this modification, the pump is mechanically similar to that previously described and is fed from the reservoir I80 through conduits I8I, IIBI, which merge into a single conduit I82 communicating with the low pressure side of the pump gears. A valve member I83 is slidably mounted in a cylindrical chamber I84, the latter being in communication with the high pressure side of the pump gears and also with the low pressure conduits I8I, IBI', I82. slidable valve member I83 is provided with a single relatively wide annular recess, one wall of which is tapered as at I85 for the purpose of operating the check valve I86. The high pressure side of the pump also communicates, through a conduit I8! with a two-stage pressure operated relief valve I88 similar to that previously described. The interior of the relief valve is in communication with the low pressure side of the pump through a. port I89, a second port I90 being provided to prevent the building up of back pressure within the relief valve.

In Figure 18 the valve member I83 is shown in jack-raising position, the check valve I88 also being shown as raised by the pressure of the fluid flowing from the high pressure side of the pump through the recess in the valve member I83, past In this embodiment, the.

the check valve I86, and into the high pressure conduit I9I. In this position of the valve member I83, the high pressure side of the pump is closed oii' from the low pressure conduits I8I, I8I', I82.

When the valve member I83 is moved into neutral or holding position as illustrated in Figure 20, the high and low pressure sides of the pump are connected through the annular recess of the member I83, by-passing the high pressure fluid and allowing the check valve I86 to close. The fluid operated device or devices are thus held in the position into which they have been moved by the high pressure fluid.

When the valve I83 is moved into lowering position as illustrated in Figure 21, the check valve I86 is positively elevated, as shown, being cammed up by the tapered surface I85 of the member I83. In this position, also, the high and low pressure sides of the pump are in communication, and the fluid flowing down through the conduit I9I and check valve I86 passes into the low pressure conduits I8I, HM, and thence into the reservoir. 1

If fluid pressure on the high pressure side of the pump becomes excessive, for example after the jack is fully raised and the valve has not been moved to neutral, the excessive pressure will be communicated through the conduit I8! into the relief valve I88, which will be actuated as previously described, .and will thereafter by-pass the fluid, at a relatively low pressure, to the reservoir.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a hydraulic apparatus for motor vehicles, a jack-supporting member having a journal portion of cylindrical form and having a fluid conduit therein,.a fluid-operatedjack mounted on said journal portion of said member for angular movement in a plane perpendicular to the axis of said member, the bearing surfaces of said jack and said member cooperating to form a channel encircling said member, said jack having an orifice communicating with said channel, and said member having an orifice communicating with said conduit and said channel, a pump adapted to force an operating fluid through said fluid conduit and into said jack, and valve means for controlling the flow of said fluid to and from said jack.

2. In a hydraulic apparatus for motor vehicles, a jack-supporting member having a journal portion of cylindrical, form and having a hollow interior, a fluid-operated jack mounted on saidment in a plane perpendicular to the axis of said member, the bearing surfaces of said jack and said member cooperating to form a circling said member, said jack having an orifice communicating with said channel, and said member having an orifice communicating with said channel, a pump, a conduit extending within said member and connecting said pump and said orifice in said member, and valve means between said pum and said orifice.

3, In a hydraulic apparatus for motor vehicles. a jack-supporting member having a journal portion of cylindrical form and having a hollow interior comprising a fluid reservoir, a fluid-operated jack mounted on said journal portion of said member for angular movement in a plane perpendicular to the axis of said member, the bearing surfaces of said jack and said member cooperating to form a channel encircling said channel 'en- 55 journal portion of said member for angular move-- member, said jack having an orifice communicating with said channel and said member having an orifice communicating with said channel, a pump supported beneath said member and adapted to draw operating fluid therefromr-conduit means connecting said pump and said "orifice in said member, and valve means between said pump and said orifice.

4. In hydraulic apparatus for motor vehicles, in combination with a motor vehicle having a frame, a jack-supporting member mounted on said frame and having a hollow interior comprising a fluid conduit and having a cylindrical journal portion, a fluid-operated jack mounted on said journal portion of said member for angular movement in a plane perpendicular to the axis of said member, the bearing surfaces of said jack and said member cooperating to form a channel encircling said member, said jack and said member, respectively, having orifices communicating with said channel, a fluid reservoir mounted on said frame, a pump, a control valve, and conduit means connecting said reservoir, pump, valve and 10 cross frame member.

CAMILLE P. GALANOT. 

